Massive white dwarf in our galaxy may go supernova

Hubble telescope picture of T Pyxidis, from a compilation of data taken on Feb. 26, 1994, and June 16, Oct. 7, and Nov. 10, 1995, by the Wide Field and Planetary Camera 2. Credit: NASA

(PhysOrg.com) -- A massive white dwarf star in our galaxy may become a supernova several million years from now, and could damage the Earth and possibly destroy life on Earth.

Scientists at the American Astronomical Society's 215th meeting, in Washington DC, said earlier this week that new observations of T Pyxidis in the constellation Pyxis (the compass) using the International Ultraviolet Explorer satellite, indicate the white dwarf is part of a close binary system with a sun, and the pair are 3,260 light-years from Earth and much closer than the previous estimate of 6,000 light-years.

The white dwarf in the T Pyxidis system is a recurrent nova, which means it undergoes nova (thermonuclear) eruptions around every 20 years. The most recent known events were in 1967, 1944, 1920, 1902, and 1890. These explosions are nova rather than supernova events, and do not destroy the star, and have no effect on Earth. The astronomers do not know why the there has been a longer than usual interval since the last nova eruption.

Astronomers believe the nova explosions are the result of an increase of mass as the dwarf siphons off hydrogen-rich gases from its stellar companion. When the mass reaches a certain limit a nova is triggered. It is unknown whether there is a net gain or loss of mass during the siphoning/explosion cycle, but if the mass does build up the so-called Chandrasekhar Limit could be reached, and the dwarf would then become a Type 1a supernova. In this event the dwarf would collapse and detonate a massive explosion resulting in its total destruction. This type of supernova releases 10 million times the energy of a nova.

Observations of the white dwarf during the nova eruptions suggest its mass is increasing, and pictures from the Hubble telescope of shells of material expelled during the previous explosions support the view. Models estimate the white dwarf's mass could reach the Chandrasekhar Limit in around 10 million years or less.

According to the scientists the supernova would result in gamma radiation with an energy equivalent to 1,000 solar flares simultaneously - enough to threaten Earth by production of nitrous oxides that would damage and perhaps destroy the ozone layer. The supernova would be as bright as all the other stars in the Milky Way put together. One of the astronomers, Dr Edward Sion, from Villanova University in Pennsylvania, said the supernova could occur "soon" on the timescales familiar to astronomers and geologists, but this is a long time in the future in human terms.

Astronomers think supernova explosions closer than 100 light years from Earth would be catastrophic, but the effects of events further away are unclear and would depend on how powerful the supernova is. The research team postulate it could be close enough and powerful enough to damage Earth, possibly severely, although other researchers, such as Professor Fillipenko of the Berkeley Astronomy Department, disagree with the calculations and believe the supernova, if it occurred, would be unlikely to damage the planet.

Related Stories

An international team of astronomers today is reporting on a discovery of a star exploding inside another star. The discovery is helping astronomers learn more about the structure of a red giant star, how shock waves move ...

In November 2008, Caroline Moore, a 14-year-old student from upstate New York, discovered a supernova in a nearby galaxy, making her the youngest person ever to do so. Additional observations determined that the object, called ...

(PhysOrg.com) -- "One of the major problems in modern astrophysics is the fact that we still do not know exactly what kinds of stellar system explode as a Type Ia supernova," says Patrick Woudt, from the University ...

Astronomers have made the best ever determination of the power of a supernova explosion that was visible from Earth long ago. By observing the remnant of a supernova and a light echo from the initial outburst, ...

Until now NGC 5584 was just one galaxy among many others, located to the West of the Virgo Cluster. Known only as a number in galaxy surveys, its sheer beauty is now revealed in all its glory in a new VLT image. ...

For astronomers, it's always been a source of frustration that the nearest white-dwarf star is buried in the glow of the brightest star in the nighttime sky. This burned-out stellar remnant is a faint companion ...

Recommended for you

Designed to detect the fossil radiation of the universe, the Planck satellite, working in tandem with Herschel, can also help to understand the macrostructure of the universe. A just-published experimental ...

A scene of jagged fiery peaks, turbulent magma-like clouds and fiercely hot bursts of bright light. Although this may be reminiscent of a raging fire or the heart of a volcano, it actually shows a cold cosmic ...

By combining observations of the distant Universe made with ESA's Herschel andPlanck space observatories, cosmologists have discovered what could be the precursors of the vast clusters of galaxies that we ...

Stars form when gravity pulls together material within giant clouds of gas and dust. But gravity isn't the only force at work. Both turbulence and magnetic fields battle gravity, either by stirring things ...

Luke Skywalker's home in "Star Wars" is the desert planet Tatooine, with twin sunsets because it orbits two stars. So far, only uninhabitable gas-giant planets have been identified circling such binary stars, ...

LOL -- that star could have gone supernova a two thosand years ago and we wouldn't know till the year 3100 rolled around. The time scales of galatic events are not for mere humans to worry on, especially if we are still getting all our information via electromagnetic radiation. -- Not that I am saying any other source exists or is detectable, but its just too slow for distances over 10 ly.

Well, it may have happened already. I wonder if the sky will become brighter and we shall see the Two Suns of Mayan/Aztec mythology on that fateful December day in 2012? Make no mistake, this is a much more real threat than the AGW lie. The difference being there is no political gain to be made from this. Come Nov, 2012 I think I may party hard just to be sure I don't waste a chance. Seeing as the nova stage is already way past due; prepare for the finale!

I wonder if the sky will become brighter and we shall see the Two Suns of Mayan/Aztec mythology on that fateful December day in 2012? Make no mistake, this is a much more real threat than the AGW lie. The difference being there is no political gain to be made from this.

...what?

This is the biggest crock of $hit I have ever heard. You don't actually believe it's very likely that anything at all unusual will happen in 2012 do you?

Someone didn't read the whole article: ..10 Million years.. don't expect anything in 2012. On the other hand, Betelgeuse is expected to become a Supernova within the next 1000 years. I has already started collapsing. It's axis is NOT pointing to Earth, so we shouldn't be fried (I HOPE THEY"RE RIGHT ABOUT THAT!!)

@Hernan: Thanks for those links. This is a pretty interesting subject - I hope to see a supernova at some point in my life. Also, that first article had a highly entertaining comment section that kept me occupied for quite a while. Thanks!

No. I don't expect anything. That is the nature of surprise isn't it? Good to get an LOL. I was serious about AGW crock. The supernova is a bigger threat. By the way, nobody can predict a supernova. Not even the most respected of astrophysicists alive. 10 million years give or take tomorrow, eh?

There will be NO supernova, the article is wrong. In 10M years, our robo-nano descendants will have already been there and will have harvested the energy and mass long before. Sheesh, just what are they teaching in school these days??

The galaxy experiences a supernova every 100 years or so (in round numbers). We are overdue. However the galaxy is large, so the chances are very small of one being overly close. There is no evidence this has happened in the last 600 million years, despite a lot of really deep mass extinction events.

On the other hand there is REALLY strong evidence of climate induced extinction events occurring much more frequently. I wouldn't count on climate stability in the long run. Its not a good bet.

Y'all say climate. I say weather.Stability is for static systems. The atmosphere ain't one. The earth evolves and so do we. 100% of all species that ever lived shall die. We shall die. I promise. Have a drink and enjoy the show.

Perhaps by the time it happens man will have evolved to a higher tolerance of radiation, because if we don't, we will not be able to travel in space. Radiation is the big killer, we need to develope an imunity to it.

Models estimate the white dwarf's mass could reach the Chandrasekhar Limit in around 10 million years or less.

The theory of relativity is just a century old, it's near impossible to predict what technology will be available a century from now. What will the Earth and humanity look like one hundred thousand centuries from now?